To achieve antenna characteristics in which an antenna is small-sized and low loss by setting an optimal condition for constituting a helical antenna consisting of core shell type magnetic body.
An antenna device comprises: an antenna element which has a helical part formed in the helical shape from a base end part or vicinity of the base end part to a tip, and in which the base end part of the helical part is connected with an electric power supply and the tip is opened; an antenna base material which consists of a cylindrical dielectric-material and which is disposed in a cavity of the helical part of the antenna element; and a magnetic material which is disposed in the antenna base material. A magnetic tangent μtanδ, which is percentage of an imaginary part to a real part in the magnetic permeability μ, needs to be 1% or less to be used as the magnetic material.
ITO NAOTO
OBA ISAO
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Katsumura Hiro
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen
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